Secondary battery and method for supplementing electrolyte of secondary battery

ABSTRACT

The present invention relates to a secondary battery and a method for supplementing an electrolyte of the secondary battery. The secondary battery according to the present invention comprises a battery case comprising an accommodation part accommodating an electrode and an electrolyte therein and a sealing member for additionally injecting the electrolyte, which is disposed on a portion of the battery case to additionally inject the electrolyte into the accommodation part of the battery case and seals an injection portion.

CROSS-REFERENCE TO RELATED APPLICATION

The present application claims the benefit of the priority of KoreanPatent Application No. 10-2016-0109485, filed on Aug. 26, 2016, which ishereby incorporated by reference in its entirety.

TECHNICAL FIELD

The present invention relates to a secondary battery and a method forsupplementing an electrolyte of the secondary battery.

BACKGROUND ART

Secondary batteries are rechargeable unlike primarily batteries, andalso, the possibility of compact size and high capacity is high. Thus,recently, many studies on secondary batteries are being carried out. Astechnology development and demands for mobile devices increase, thedemands for secondary batteries as energy sources are rapidlyincreasing.

Secondary batteries are classified into coin type batteries, cylindricaltype batteries, prismatic type batteries, and pouch type batteriesaccording to a shape of a battery case. In such a secondary battery, anelectrode assembly mounted in a battery case is a chargeable anddischargeable power generating device having a structure in which anelectrode and a separator are stacked.

The electrode assembly may be approximately classified into a jelly-rolltype electrode assembly in which a separator is interposed between apositive electrode and a negative electrode, each of which is providedas the form of a sheet coated with an active material, and then, thepositive electrode, the separator, and the negative electrode are wound,a stacked type electrode assembly in which a plurality of positive andnegative electrodes with a separator therebetween are sequentiallystacked, and a stack/folding type electrode assembly in which stackedtype unit cells are wound together with a separation film having a longlength.

Recently, the pouch-type battery in which a stack/folding type electrodeassembly is built in a pouch-type battery case provided as an aluminumlamination sheet is attracting much attention due to its lowmanufacturing cost, small weight, easy shape deformation, and the like,and thus, its usage is gradually increasing.

DISCLOSURE OF THE INVENTION Technical Problem

One aspect of the prevent invention is to provide a secondary battery inwhich an electrolyte is capable of being additionally injected and whichis resealed after the injection of the electrolyte and a method forsupplementing the electrolyte of the secondary battery.

Technical Solution

A secondary battery according to an embodiment of the present inventionmay comprise a battery case comprising an accommodation partaccommodating an electrode and an electrolyte therein and a sealingmember for additionally injecting the electrolyte, which is disposed ona portion of the battery case to additionally inject the electrolyteinto the accommodation part of the battery case and seals an injectionportion, wherein the sealing member for additionally injecting theelectrolyte passes through the inside and outside of the battery case sothat the electrolyte is injected through a penetrated portion of thesealing member.

A method for supplementing an electrolyte of a secondary batteryaccording to an embodiment of the present invention may comprise aninjection preparation process of allowing an injection needle to passthrough a sealing member for additionally injecting the electrolyte,which passes through the inside and outside of a battery case and isformed on a portion of the battery case so that the injection needlepasses through a penetrated portion of the sealing member to inject theelectrolyte, an injection process of additionally injecting theelectrolyte into an accommodation part of the battery case, in which anelectrode assembly and the electrolyte are accommodated, through theinjection needle, and a sealing process of sealing the portion of thesealing member, through which the injection needle passes, after theinjection needle is removed from the sealing member for additionallyinjecting the electrolyte.

Advantageous Effects

According to the present invention, the sealing member for additionallyinjecting the electrolyte may be disposed on a portion of the batterycase to additionally inject the electrolyte into the battery. After theelectrolyte is injected, the sealing member may be resealed.

Also, the sealing member for additionally injecting the electrolyte maybe made of the thermoplastic member. Thus, when heat is applied, thesealing member may have fluidity so that the needle for injecting theelectrolyte easily passes through the sealing member. When heat isapplied after the injection needle is removed, the portion of thesealing member, through which the needle passes, may be easily sealed.Here, the thermoplastic member may be made of the silicone sealant.Thus, even when the thermal treating process is performed, the sealingmember for additionally injecting the electrolyte may be minimized inmaterial damage thereof. Thus, the repetitive and additional supplementof the electrolyte may be easy.

Also, the sealing member for additionally injecting the electrolyte maybe provided as the highly contractive member to seal the penetratedportion by the self-contacting force thereof when the injection needleis removed, thereby sealing the sealing member for additionallyinjecting the electrolyte without performing separate sealingprocessing.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a secondary battery according to a firstembodiment of the present invention.

FIG. 2 is a cross-sectional view illustrating a main part of thesecondary battery according to the first embodiment of the presentinvention.

FIG. 3 is a cross-sectional view illustrating a main part of a secondarybattery according to a second embodiment of the present invention.

FIG. 4 is a cross-sectional view illustrating a main part of a secondarybattery according to a third embodiment of the present invention.

FIG. 5 is a cross-sectional view illustrating a main part of a secondarybattery according to a fourth embodiment of the present invention.

FIG. 6 is a view illustrating an example of an injection preparationprocess and an injection process in a method for supplementing anelectrolyte of a secondary battery according to an embodiment of thepresent invention.

FIG. 7 is a view illustrating an example of a state in which theinjection needle is removed after the electrolyte is injected in themethod for supplementing the electrolyte according to an embodiment ofthe present invention.

FIG. 8 is a view illustrating an example of a sealing process in themethod for supplementing the electrolyte according to an embodiment ofthe present invention.

FIG. 9 is a view illustrating another example of the sealing process inthe method for supplementing the electrolyte according to an embodimentof the present invention.

FIG. 10 is a view illustrating further another example of the sealingprocess in the method for supplementing the electrolyte according to anembodiment of the present invention.

MODE FOR CARRYING OUT THE INVENTION

The objectives, specific advantages, and novel features of the presentinvention will become more apparent from the following detaileddescription taken in conjunction with the accompanying drawings. Itshould be noted that the reference numerals are added to the componentsof the drawings in the present specification with the same numerals aspossible, even if they are illustrated in other drawings. Also, thepresent invention may be embodied in different forms and should not beconstrued as limited to the embodiments set forth herein. In thefollowing description of the present invention, the detaileddescriptions of related arts which may unnecessarily obscure the gist ofthe present invention will be omitted.

FIG. 1 is a perspective view of a secondary battery according to a firstembodiment of the present invention, and FIG. 2 is a cross-sectionalview illustrating a main part of the secondary battery according to thefirst embodiment of the present invention.

Referring to FIGS. 1 and 2, a secondary battery 100 according to a firstembodiment of the present invention comprises a battery case 110accommodating an electrode assembly 120 and an electrolyte G and asealing member 130 for additionally injecting the electrolyte G, whichis disposed on a portion of the battery case 110.

Hereinafter, the secondary battery according to the first embodiment ofthe present invention will be described in more detail with reference toFIGS. 1 and 2.

The battery case 110 comprises a first case 111 and a second case 112and also comprises an accommodation part 113 accommodating the electrodeassembly 120 and the electrolyte G therein. Here, the battery case 110has a space part 113 a in which the electrode assembly 120 is notdisposed in the accommodation part 120. Here, the space part 113 a isformed in the battery case 110 so that the sealing member 130 foradditionally injecting the electrolyte G is adjacent to the space part113 a.

The electrode assembly 120 may be a chargeable and dischargeable powergeneration element and have a structure in which an electrode 123 and aseparator 124 are combined and alternately stacked. Also, the electrodeassembly 120 may comprise an electrode lead 125 electrically connectedto the electrode 123.

The electrode 123 may comprise a positive electrode 121 and a negativeelectrode 122. Here, the electrode assembly 120 may have a structure inwhich the positive electrode 121/the separator 124/the negativeelectrode 122 are alternately stacked.

The separator 124 is made of an insulation material to electricallyinsulate the positive electrode 121 from the negative electrode 122.Here, the separator 124 may be made of, for example, a polyolefin-basedresin film such as polyethylene or polypropylene having micropores.

The sealing member 130 for additionally injecting the electrolyte G maybe disposed on a portion of the battery case 110 so that an injectionportion of the battery case 110 is sealed after the electrolyte G isadditionally injected into the accommodation part 113 of the batterycase 110.

Also, the sealing member 130 for additionally injecting the electrolyteG may be provided to pass through the inside and outside of the batterycase 110 so that a portion of the sealing member 130 is penetrated forinjecting the electrolyte G.

Furthermore, the sealing member 130 for additionally injecting theelectrolyte G may be made of a thermoplastic member. Thus, when heat isapplied, the sealing member may have fluidity so that an injectionneedle easily passes through the sealing member. When heat is appliedafter the injection needle is removed, the injection portion having athrough-hole, through which the injection needle passes, may be easilysealed.

Here, the thermoplastic member may be made of, for example, a siliconesealant. Thus, when heat is applied to the sealing member 130 foradditionally injecting the electrolyte G, the fluidity may be moreimproved so that the injection need more easily passes through thesealing member 130. Also, although the thermal treating process isrepeatedly performed, the material damage of the sealing member 130 foradditionally injecting the electrolyte G may be minimized. In addition,when the injection needle is removed after heat is applied to allow theinjection needle to pass, and then heat is applied again, the injectionportion may return to its original shape. That is, when the heat isapplied to the penetrated portion of the sealing member 130 foradditionally injecting the electrolyte G while the injection isperformed, the penetrated portion may be filled to completely seal theinjection portion.

FIG. 3 is a cross-sectional view illustrating a main part of a secondarybattery according to a second embodiment of the present invention.

Referring to FIG. 3, a secondary battery 200 according to anotherembodiment of the present invention further comprises a protrusion end214 on a battery case 210 to support the sealing member 230 foradditionally injecting the electrolyte G, thereby preventing the sealingmember 230 from being separated from the battery case 210.

Here, the protrusion end 214 protrudes from each of inner and outersurfaces of the battery case 210 in a direction of the sealing member230 for additionally injecting the electrolyte G to support the sealingmember 230 for additionally injecting the electrolyte G, therebypreventing the sealing member 230 from being separated toward the insideand outside of the battery case 210. Here, for example, the protrusionend 214 may protrude to be disposed along an edge of each of upper andlower end of the sealing member 230 for additionally injecting theelectrolyte G.

FIG. 4 is a cross-sectional view illustrating a main part of a secondarybattery according to a third embodiment of the present invention.

Referring to FIG. 4, a secondary battery 300 according to a thirdembodiment of the present invention comprises a battery case 310accommodating an electrode assembly 120 and an electrolyte G, a sealingmember 330 for additionally injecting the electrolyte G, which isdisposed on a portion of the battery case 310, and a sealing tape 340attached to the sealing member 330 for additionally injecting theelectrolyte G.

The secondary battery 300 according to the third embodiment of thepresent invention is different from the secondary battery 100 accordingto the first embodiment and the secondary battery 200 according to thesecond embodiment in that the sealing member 330 for additionallyinjecting the electrolyte G is provided as a highly contractive memberto allow the sealing tape 340 to the sealing member 330 for additionallyinjecting the electrolyte G. Thus, contents of this embodiment, whichare duplicated with those according to the first and second embodiments,will be briefly described, and also, differences therebetween will bemainly described.

In more detail, the sealing member 330 for additionally injecting theelectrolyte G may be provided as the highly contractive member, and thusan injection portion may be sealed by self-contracting force thereof.Here, the highly contractive member may be made of, for example,silicone rubber.

Also, the sealing tape 340 may be attached to an outer surface of thesealing member 330 for additionally injecting the electrolyte G toadditionally seal the injection portion. Here, the sealing tape 340 maybe provided as, for example, Kapton tape. Here, the Kapton tape may beexcellent in heat resistance, cold resistance, chemical resistance,insulation, withstand voltage, and the like to improve sealability,thereby protecting the sealing member 330 for additionally injecting theelectrolyte G against various environments.

FIG. 5 is a cross-sectional view illustrating a main part of a secondarybattery according to a fourth embodiment of the present invention.

Referring to FIG. 5, a secondary battery 400 according to a fourthembodiment of the present invention comprises a battery case 410accommodating an electrode assembly 120 and an electrolyte G and asealing member 430 for additionally injecting the electrolyte G, whichis disposed on a portion of the battery case 410. Here, in the secondarybattery 400 according to the fourth embodiment of the present invention,the sealing member 430 for additionally injecting the electrolyte G maycomprise a thermoplastic member, a highly contractive member, a heatdissipation member 433.

The secondary battery 300 according to the third embodiment of thepresent invention is different from the secondary battery 100 accordingto the first embodiment, the secondary battery 200 according to thesecond embodiment, and the secondary battery 300 according to the thirdembodiment in that the sealing member 430 for additionally injecting theelectrolyte G comprises the thermoplastic member, the highly contractivemember, the heat dissipation member 433. Thus, contents of thisembodiment, which are duplicated with those according to the first,second, and third embodiments, will be briefly described, and also,differences therebetween will be mainly described.

In more detail, in the sealing member 430 for additionally injecting theelectrolyte, an outer part 431 of the sealing member 430 with respect toan accommodation part of the battery case 410 may be provided as thethermoplastic member to seal the injection portion by applying heat.Also, the inner part 432 of the sealing member 430 may be provided asthe highly contractive member to seal the injection portion byself-contracting force thereof. Here, the thermoplastic member may bemade of a silicone sealant, and the highly contractive member may bemade of silicone rubber. Thus, the injection portion of the sealingmember 430 for additionally injecting the electrolyte G may be doublysealed to provide more sealing force.

Also, the sealing member 430 for additionally injecting the electrolyteG may further comprise the heat dissipation member 433 disposed betweenan outer part 431 and an inner part 432 to block heat transfer betweenthe outer part 431 and the inner part 432. Here, the heat dissipationmember 433 may be made of a Kapton material. Here, the heat dissipationmember 433 may be provided as, for example, a Kapton tape.

FIG. 6 is a view illustrating an example of an injection preparationprocess and an injection process in a method for supplementing anelectrolyte of a secondary battery according to an embodiment of thepresent invention, FIG. 7 is a view illustrating an example of a statein which the injection needle is removed after the electrolyte isinjected in the method for supplementing the electrolyte according to anembodiment of the present invention, and FIG. 8 is a view illustratingan example of a sealing process in the method for supplementing theelectrolyte according to an embodiment of the present invention.

Hereinafter, a method for supplementing an electrolyte of a secondarybattery according to an embodiment of the present invention will bedescribed in more detail with reference to FIGS. 6 to 10.

Referring to FIGS. 6 to 8, the method for supplementing the electrolyteof the secondary battery according to an embodiment of the presentinvention comprises an injection preparation process, an injectionprocess, and a sealing process. Also, the method for supplementing theelectrolyte of the secondary battery according to an embodiment of thepresent invention may further comprise a tape attaching process.

In more detail, referring to FIG. 6, in the injection preparationprocess, an injection needle 11 passes through a sealing member 130 foradditionally injecting the electrolyte G, which passes through theinside and outside of a battery case 110 and is formed on a portion of abattery case 110 so that the injection needle 11 passes through apenetrated portion of the sealing member to inject the electrolyte G.

Also, in the injection preparation process, the injection needle 11 maypass through the sealing member 130 for additionally injecting theelectrolyte G so that the electrolyte G is additionally injected into aspace part 113 a, in which the electrode assembly 120 is not disposed inan accommodation part 113 of the battery case 110, through the sealingmember 130 for additionally injecting the electrolyte G.

Furthermore, in the injection preparation process, heat may be appliedto the sealing member 130 for additionally injecting the electrolyte G,which is provided as a thermoplastic member, so that the injectionneedle 11 easily passes through the sealing member 130. As a result, thesealing member 130 may change in fluidity so that the injection needle11 passes therethrough.

In the injection process, the electrolyte G may be additionally injectedinto the accommodation part 113 of the battery case 110, in which theelectrode assembly 120 and the electrolyte G are accommodated, throughthe injection needle 11.

Here, in the injection process, for example, the electrolyte G may beaccommodated in the injection needle 10 and then be additionallyinjected into the accommodation part 113 of the battery case 110 throughthe injection needle 11 passing through the sealing member 130 foradditionally injecting the electrolyte G.

Referring to FIG. 7, in the sealing process, after the injection needle11 is removed from the sealing member 130 for additionally injecting theelectrolyte G, a through-hole H formed by the penetration of theinjection needle 11 may be sealed.

Also, referring to FIG. 8, in the sealing process, heat is applied tothe sealing member 130 for additionally injecting the electrolyte G,which is provided as, for example, the thermoplastic member to seal theportion of the sealing member 130, through which the injection needlepasses. Here, in the sealing process, heat is applied to the sealingmember 130 for additionally injecting the electrolyte G, which is madeof a silicone sealant, to seal the penetrated portion.

FIG. 9 is a view illustrating another example of the sealing process inthe method for supplementing the electrolyte according to an embodimentof the present invention.

In addition, referring to FIG. 9, for another example, in the sealingprocess, the sealing member 330 for additionally injecting theelectrolyte G may be provided as a highly contractive member. Thus, whenthe injection needle is removed from the sealing member 330 foradditionally injecting the electrolyte G, the portion of the sealingmember 330, through which the injection needle passes, may be sealed byself-contracting force of the highly contractive member. Here, thehighly contractive member may be made of, for example, silicone rubber.

Here, in the tape attaching process, a sealing tape 340 may be attachedto an outer surface of the sealing member 330 for additionally injectingthe electrolyte G to additionally seal the injection portion that issealed by the self-contracting force of the highly contractive member.Here, the sealing tape 340 may be provided as a Kapton tape.

Here, in the tap attaching process, the sealing tape 340 may be attachedbefore the injection preparation process. In the injection preparationprocess, a portion or the whole of the sealing tape 340 may be separatedfrom the sealing member 330 for additionally injecting the electrolyteG, and then, the injection needle may pass through the sealing member330 for additionally injecting the electrolyte G. In the sealingprocess, the injection needle may be removed from the sealing member 330for additionally injecting the electrolyte G, and then, a portion of thesealing tape 340, which is separated from the sealing member 330 foradditionally injecting the electrolyte G, may be attached again to thesealing member 330 for additionally injecting the electrolyte G toadditionally seal the sealing member 330.

FIG. 10 is a view illustrating further another example of the sealingprocess in the method for supplementing the electrolyte according to anembodiment of the present invention.

Also, referring to FIG. 10, for further another example, in the sealingprocess, an inner part 432 of the sealing member 430 for additionallyinjecting the electrolyte G, which is made of the silicone rubber, withrespect to the accommodation part 413 of the battery case may seal theportion, through which the injection needle passes, by theself-contracting force of the silicon rubber when the injection needleis removed. In addition, heat may be applied to an outer part 431 of thesealing member 430 for additionally injecting the electrolyte G, whichis made of the silicone sealant, to seal the penetrated portion of thesealing member 430.

Here, in the sealing process, heat transfer between the outer part 431and the inner part 432 may be blocked by a heat dissipation member 433disposed between the outer part 431 and the inner part 432 of thesealing member 430 for additionally injecting the electrolyte G. Here,the heat dissipation member 433 may be provided as, for example, aKapton tape.

While the present invention has been particularly shown and describedwith reference to exemplary embodiments thereof, this is for the purposeof specifically describing the present invention, and thus, thesecondary battery and the method for supplementing the electrolyte ofthe secondary battery according to the present invention are not limitedthereto. It will be understood by those of ordinary skill in the artthat various changes in form and details may be made therein withoutdeparting from the spirit and scope of the invention.

Furthermore, the scope of protection of the present invention will beclarified by the appended claims.

1. A secondary battery comprising: a battery case comprising an accommodation part accommodating an electrode and an electrolyte therein; and a sealing member for additionally injecting the electrolyte, which is disposed on a portion of the battery case to additionally inject the electrolyte into the accommodation part of the battery case and seals an injection portion, wherein the sealing member for additionally injecting the electrolyte passes through the inside and outside of the battery case so that the electrolyte is injected through a penetrated portion of the sealing member.
 2. The secondary battery of claim 1, wherein the sealing member for additionally injecting the electrolyte is provided as a thermoplastic member so that the injection portion is sealed by applying heat.
 3. The secondary battery of claim 2, wherein the thermoplastic member is made of a silicone sealant.
 4. The secondary battery of claim 1, wherein the sealing member for additionally injecting the electrolyte is provided as a highly contractive member so that the injection portion is sealed by self-contracting force thereof.
 5. The secondary battery of claim 4, wherein the highly contractive member is made of silicone rubber.
 6. The secondary battery of claim 5, further comprising a sealing tape attached to an outer surface of the sealing member for additionally injecting the electrolyte to additionally seal the injection portion.
 7. The secondary battery of claim 1, wherein, in the sealing member for additionally injecting the electrolyte, an outer part of the sealing member with respect to the accommodation part of the battery case is made of a silicone sealant to seal the injection portion by applying heat, and an inner part of the sealing member is made of silicone rubber to seal the injection portion through self-contracting force thereof.
 8. The secondary battery of claim 7, wherein the sealing member for additionally injecting the electrolyte further comprises a heat dissipation member disposed between the outer part and the inner part to block heat transfer between the outer part and the inner part.
 9. The secondary battery of claim 1, wherein the battery case further comprises a protrusion end protruding from each of inner and outer surfaces of the battery case in a direction of the sealing member for additionally injecting the electrolyte to support the sealing member for additionally injecting the electrolyte, thereby preventing the sealing member from being separated from the battery case.
 10. A method for supplementing an electrolyte of a secondary battery, the method comprising: an injection preparation process of allowing an injection needle to pass through a sealing member for additionally injecting the electrolyte, which passes through the inside and outside of a battery case and is formed on a portion of the battery case so that the injection needle passes through a penetrated portion of the sealing member to inject the electrolyte; an injection process of additionally injecting the electrolyte into an accommodation part of the battery case, in which an electrode assembly and the electrolyte are accommodated, through the injection needle; and a sealing process of sealing the portion of the sealing member, through which the injection needle passes, after the injection needle is removed from the sealing member for additionally injecting the electrolyte.
 11. The method of claim 10, wherein, in the injection preparation process, the injection needle passes through the sealing member for additionally injecting the electrolyte after heat is applied to the sealing member provided as a thermoplastic member so that the injection needle easily passes through the sealing member, and in sealing process, heat is applied to the sealing member for additionally injecting the electrolyte provided as a thermoplastic member to seal the portion of the sealing member, through which the injection needle passes.
 12. The method of claim 11, wherein, in the sealing process, heat is applied to the sealing member for additionally injecting the electrolyte made of a silicone sealant to seal the penetrated portion.
 13. The method of claim 10, wherein, in the sealing process, the sealing member for additionally injecting the electrolyte is made of silicone rubber to seal the portion of the sealing member, through which the injection needle passes, by self-contracting force of the silicone rubber when the injection needle is removed from the sealing member for additionally injecting the electrolyte.
 14. The method of claim 12, further comprising a tape attaching process of attaching a sealing tape to an outer surface of the sealing member for additionally injecting the electrolyte.
 15. The method of claim 14, wherein, in the tape attaching process, the sealing tape is attached before the injection preparation process, in the injection preparation process, the injection needle passes through the sealing member for additionally injecting the electrolyte after a portion or the whole of the sealing tape is separated from the sealing member for additionally injecting the electrolyte, and in the sealing process, the portion of the sealing tape, which is separated from the sealing member for additionally injecting the electrolyte, is attached again to the sealing member for additionally injecting the electrolyte to additionally seal the sealing member after the injection needle is removed from the sealing member for additionally injecting the electrolyte.
 16. The method of claim 10, wherein, in the sealing process, an inner part of the sealing member for additionally injecting the electrolyte, which is made of the silicone rubber, with respect to the accommodation part of the battery case seals the portion, through which the injection needle passes, by self-contracting force of the silicon rubber when the injection needle is removed, and heat is applied to an outer part of the sealing member for additionally injecting the electrolyte, which is made of a silicone sealant, to seal the penetrated portion of the sealing member.
 17. The method of claim 13, further comprising a tape attaching process of attaching a sealing tape to an outer surface of the sealing member for additionally injecting the electrolyte.
 18. The method of claim 17, wherein, in the tape attaching process, the sealing tape is attached before the injection preparation process, in the injection preparation process, the injection needle passes through the sealing member for additionally injecting the electrolyte after a portion or the whole of the sealing tape is separated from the sealing member for additionally injecting the electrolyte, and in the sealing process, the portion of the sealing tape, which is separated from the sealing member for additionally injecting the electrolyte, is attached again to the sealing member for additionally injecting the electrolyte to additionally seal the sealing member after the injection needle is removed from the sealing member for additionally injecting the electrolyte. 